The desirability of providing pitch and tilt control for a dozer blade has long been recognized. Changes in pitch, i.e. fore and aft movement of the top of the blade by rotation of the blade about a transverse, essentially horizontal, axis near the bottom of the blade, have been effected by extension or retraction of a pair of hydraulic rams; one ram connected between the blade and each of the push arms. Changes in tilt, i.e. raising or lowering one edge or corner of the blade relative to the other corner, have been effected by extension or retraction of only one of these rams. While the mechanics of pitch and tilt have been known for some time, the hydraulic control thereof has been a problem. It is therefore, an object of this invention to provide a hydraulic control for a dozer blade which will permit both tilt and pitch functions with precision and accuracy.
It is also an object of this invention to provide such a hydraulic control which will permit changes in tilt without alteration of pitch and vice versa, within the mechanical limits of the dozer mechanism.
It is also an object of this invention to provide such a hydraulic control which minimizes cost while preserving accuracy and precise control.